Electrical hot-plate.



R. W. DAVENPORT. ELECIRICAL HOT PLATE. APPLICATION FILED OCT. I0. 1914' Patented Nov. 2, 1915.

. WITNESSES. l/VVE/VTOH 12 2723 777 W czrenporf /Q% BY 2/ L W m 1477 ORA/E 7/ Application filed October 10, 1914.

UNITED STATES PATENT ()FFICE,

RANSOM W. DAVENPORT, OF DETROIT, MICHIGAN, ASSIGNOR TO DETROIT STOVE WORKS, OF DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN.

ELECTRICAL HOT-PLATE.

'1 0 all whom it may concern:

Be it known'that I, RAN-$0M W. DAVEN- PORT, a citizen of the United States of America, residing at Detroit, in the county of \Vayne and State of Michigan, have invented certain new and useful Improvements in Electrical Hot-Plates, of which the following is a specification, reference being had therein to the accompanying drawings. I

The invention relates to electric heaters and more particularly to constructions designed for use as hot-plates. It is the object of the invention, first, to obtain a construction in which a substantial support is afforded for the hot-plate with a minimum loss of heat.

It is a further object to obtain a construction which is easily assembled and replaceable, and further to provide freedom for expansion and contraction of the unit.

In the drawing, Figure 1 is a plan view; Fig. 2 is a cross section.

A is a plate forming the top of the stove, which is cut away at B for the electric hotplates C. These hot-plates, which are electrically heated by any suitable construction (not shown), are provided with heat distributing top surfaces of an area to substantially fill the opening or cut away portion B. It is, however, desirable to prevent the loss of heat from the lower face of the heater and also from the marginal edge thereof and through the mechanical supports. To this end I have devised a construction in which-the heat losses are minimized as follows. The edge of the plate A adjacent to the aperture B is preferably tapered to a thin or substantial knife edge I), which is separated by an air space from the periphery of the hot-plate C.

E is a heat-reflecting ring surrounding the hot-plate G and the space intermediate the same a the knife edge D.

F is a body of thermal insulation arranged beneath the plate C and held in a suitable casing Gr.

H are supports distributed around the hot-plate, being preferably three in number and being preferably in the form of U- Specification of Letters Patent.

Patented Nov. 2, 1915.

Serial No. 866,075.

shaped brackets, the outer ends of which are secured to the bottom of the top plate A, while their inner ends are stepped to form supports for the hot-plate C, the ring E and the casing G containing the thermal insulation F. The brackets H are of a cross section which will secure the requisite strength for mechanical support with a minimum area for the conduction of heat, while the length resulting from the returnbent or U- shaped form will greatly impede heat conduction. Furthermore, the step shoulder I which supports the heater C is limited to an exceedingly small area to avoid heat conduction. The shoulder J which supports the casing G is positioned to hold this casing and the insulation F contained thereby below and out of contact with the hot-plate C, leaving an air space therebetween. The shoulder K, which supports the ring E is also positioned to space said ring from the periphery of the hot-plate C and the knife edge D of the plate A. The dissipation of heat excepting through the upper or work surface of the plate is very slight and at the same time a substantial support is afforded for the plate, and the latter is substantially continuous with the top plate A. The upper surface of the plate C is slightly elevated above the plane of the plate A to hold the heated vessel out of contact with the latter.

The hot-plate C may be made readily removable by providing it with a depending lug Ii having contacts M for engaging the cooperating contacts in a terminal connection N secured to the bottom of the casing G. This permits of detaching the plate C by merely lifting it ofi from its support, and upon replacing it upon the support the electrical connections are automatically made.

What I claim as my invention is l. The combination with an electrically heated hot-plate, a deflector ring inclosing the same, and a thermal insulation beneath the same, of a common support for said hotplate, ring and insulation, each of the same being separately removable from said support.

2. The combination with an apertured plate, of an electrical hot-plate located in the aperture and spaced from the edge thereof, and substantially U-shaped supports secured to said apertured plate andhaving bearings at their opposite ends for loosely supporting said hot-plate and stepped to maintainthe hot-plate centered within said aperture.

3. The combination with an apertured plate, of an electrical hot-plate arranged in the aperture of said plate, thermal insulation for the bottom of said hot-plate, and brackets secured to and depending from the apertured plate, supporting the hot plate in a spaced relation to the edge of said aperture and supporting the insulation in a spaced relation to the bottom of the hotplate.

4. The combination with an apertured plate, of an electrical hot-plate located in the aperture and spaced. from the edge thereof, a reflecting ring surrounding said hot-plate and spaced therefrom and from the edge of the apertured plate, thermal insulation below said hot-plate, and a plurality of U-shaped brackets secured to and depending from said apertured plate and having stepped bearings for supporting said hot-plate, reflector ring and thermal insulation.

5. The combination with an electrical hotplate, of a plate apertured to receive said hot plate and having the edge of the aperture tapered to a thin edge to limit the heat conducting surface, a reflector ring interposed between the hot-plate and said tapered edge, and means for indirectly supporting said hot-plate from said apertured plate.

6. The combination with an :apertured plate having the margin surrounding the aperture tapered to a thin edge, of an electrical hot-plate located in said aperture, a reflector ring surrounding the periphery of said hot-plate spaced therefrom and from said thin edge, thermal insulation below said hot plate, and a bracket secured to said apertured plate extending indirectly to said hot-plate and supporting the same together with said ring and thermal insulation.

7. The combination with an apertured plate, of a hot-plate located in said aperture, thermal insulation below said plate, said hot-pl ate and insulator being relatively movable, electrical connection for said hot-plate having contacts fixedly located in said thermal insulation, and cooperating contacts on said hot-plate for detachably engaging said first-mentioned contacts.

8. The combination with an apertured plate, of a plurality of U-shaped brackets secured thereto and having stepped bearings at their inner ends, an electrical hot-plate coated in said aperture supported on one of the steps of said bearing, a casing below said hot-plate supported on another of said bearings, thermal insulation in said casing, a heat-reflecting ring surrounding said hotplate spaced from the same and the edge of the aperture and supported upon another step of the bearing, electrical contacts carried by said casing, and cooperating contacts on said hot-plate detachably engaging said first-mentioned contacts.

9. The combination with an electrically heated hot plate, of a reflector ring inclosing said plate and spaced therefrom, and a plurality of common supports for said plate and ring maintaining their spaced relation.

10. The combination with an electricallyheated hot-plate, of a reflector ring inclosing the same, and a thermal insulation spaced beneath the hot-plate, and means forming a common support for the hot-plate, reflector ring and insulation.

1.1. The combination with an electrically heated hot-plate, of a reflector ring inclosing the same and spaced therefrom, a thermal insulation spaced beneath the hot-plate, and a plurality of common supports for the hot-plate, reflector ring and insulation maintaining the same in their proper spaced relation.

12. The combination with an electricallyheated hot-plate, of thermal insulation spaced below the hot-plate, and a plurality of common supports for the insulation and hot-plate, maintaining the spaced relation between the same.

13. The combination with an electrically heated hot-plate, of a reflector ring inclosing the same, and spaced therefrom, a thermal insulation spaced from the hot-plate beneath the same, and a plurality of members similarly stepped to support said hot-plate, reflector ring and insulation and maintain the desired spaced relation between the same.

14. The combination with supporting means, of an electrically-heated hot-plate carried by said means, and free to be lifted therefrom, and cooperating electrical contacts guided into or out of engagement with each other when the plate is being removed or replaced, by the engagement of said plate with said supporting means.

15. The combination with an electricallyheated hot-plate, of a thermal insulation beneath the same, a common support for the hot-plate and insulation, the hot-plate being removable from said support independently of the insulation, contact members carried by the hot-plate projecting into an opening in the insulation and contact members with which those carried by the hot-plate are engaged or disengaged according as said plate is displaced to or from its normal position.

heated hot-plate, and an incased thermal insulation beneath said hot-plate, of cooperatsaid plate is being removed or replaced by ing contact members respectively carried by engagement of said plate with the support. 10

the hot-plate and insulation, and a common In testimony whereof I affix my signature support for the hot-plate and insulation, the in presence of two witnesses.

hot-plate being removable from said sup- RANSOM \V. DAVENPORT. port independently of said insulation, the \Vitnesses: cooperating members being guided out of JAMES P. BARRY,

or into engagement with each other when HENRI E. BOWMAN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. G. Y 

